On 03/14/17 12:08, Kyle Huey wrote:
>
> That's largely what we ended up doing. See
> https://lkml.org/lkml/2017/2/14/80 and the latest version of this
> patch, https://lkml.org/lkml/2017/3/11/197.
>
Yes, as I said, my mistake.
I would still like to see an early-out when none of these flags are set
(I just discussed this with tglx on IRC):
if (likely(!((tifp|tifn) &
(_TIF_BLOCKSTEP|_TIF_NOTSC|_TIF_IO_BITMAP|
_TIF_NOCPUID|_TIF_USER_RETURN_NOTIFY))))
return;
The USER_RETURN_NOTIFY could really use some sanity: it is a notifier
chain with a single in-kernel user, which is KVM on x86 only, but we
most likely will need to propagate the flag even if it ends up getting
specialized.
-hpa
